How To Race Engine For Preventative Maintenance?

R

rd_volvo

New member
I've read that it's good to run your car at 5000 rpm's

for a certain amount of time once a year to clean out the upper

engine components and keep engine performing nicely.

I have a 5 speed. What's the best way to do this without

harming the engine.



ty

rd

99c70
 
I'd just take it out on your favorite back roads (I prefer the twisties), leave it in 2nd or 3rd and have some fun.



Oddly, most engine stress comes while revving down; like, say you were driving hard, upshifting and downshifting, using the engine to assist with braking - that's when the crank, rods and pistons see the most load...one would think it would be during rev-up.
 
cheaper to just leave it in first or second and hold it up there on a relatively open road..

Geeky, thats why they say its cheaper to replace brake parts than engine parts... right?

Dana
 
If most of your driving is stop start stuff it is good to let the engine breathe heavily every now and then. I drive an Alfa, where it is encouraged to drive for a few miles between 4-6000 rpm, particularly after a lot of urban driving. Give it a try and your engine should fell better afterwards. Bizzy928 is correct, let everything warm up first.
 
You got it, dboat - that, and I think the old addage used to be that clutches were more expensive than brakes (with the engine braking issue).



In response to the warm-up before WOT, that's another excellent point (can't believe I missed it), but one note of caution:



Make sure your engine oil is up to temperature - don't rely on the water temp gauge to indicate when the car is "warm". Water heats at about 3:1 ratio than the oil does, so even after your water temp shows "normal", chances are the oil isn't quite yet up to temp yet.



I've found that it takes about 10 minutes of normal driving to get the oil warm and about 15-20 minutes to get it to true operating temperature.
 
I regularly rev my engine on the open road to 5k+ to remind my engine that it's a performance machine :)



I don't see how downshifting is any harder on the car than upshifting anyway, it's the same only in reverse, and in automatic transmissions, it automatically downshifts as you brake, so downshifting in a 5-6spd is essentially the same thing, as long as you don't rev down from a high RPM all the time, be sure to put most pressure on the brakes. I try to keep my downshifts at the 3k mark every time I down it....such as, at 40mph I can downshift to 3rd without a jolt and keeps it under a good RPM, 25mph to 2nd, and from there I drift to a stop using brakes only with the clutch in.



Assist the brakes by downshifting, not downshifting to assist the brakes. Brake pads are cheap, clutches aren't.
 
I think the only problem with downshifting creating a huge load is if you don't blip the throttle to match revs. Shifting heel-toe will always allow you to match revs so it's a non-issue anyway. If anyone is going to be hamfisted and jam the tranny into 1st gear at 30 mph, then it really doesn't matter how good you are with the brakes.
 
DinosGSR said:
I don't see how downshifting is any harder on the car than upshifting anyway, it's the same only in reverse, and in automatic transmissions, it automatically downshifts as you brake, so downshifting in a 5-6spd is essentially the same thing.....
Click to expand...



While you'd think that's true, automatic transmissions have clutches and torque convertors which off-load drivetrain resistance to the motor during "downshifts" and "deacceleration" (under most circumstances). The clutches in the transmission slip, the torque convertor locks or unlocks to help reduce load on the engine...



I used to build NHRA Super Gas and Super Comp motors (along with some IMSA and REMAX circle track motors) for a number of years, and studied engine wear and load bearing effects quite heavily. We had a study that we often referred to that showed that the most rod/piston distortion occurs while an engine is revving down - odd, but true.



So much so, that if you go to an NHRA event, you'll find that the big HP motors go from WOT to closed throttle the second the chute is opened - they usually don't "rev down" while slowing the cars, even from 300MPH where engine braking would be a tremendous benefit. Of course, those engines are already on the limit of durability, so it's a bit of an extreme example.
 
Would you say the aforementioned is good for all motors ? In other words, does a 5.2 V-8, need to be opened up, regularly ? (Weekly, monthly, once every tank full )
 
Patrick said:
Would you say the aforementioned is good for all motors ? In other words, does a 5.2 V-8, need to be opened up, regularly ? (Weekly, monthly, once every tank full )
Click to expand...



At least daily! ;)



A couple times a week is fine. Just romp on it when getting on the freeway a few times. Also, run a good upper end cleaner through the engine once in a while. I just had that done to my Accord and the improvement in performance was immediately noticable, and I get on the throttle regularly. You just get deposits and gunk that form on the back side of the valves that eventually impede flow into and out of the cylinder head(s). Probably made such a difference in mine because it was done at 253,000 miles for the very first time! If you get it done regularly, the difference won't be nearly as noticable, but your perfomance won't fall off either.
 
Taking the car out for a little spirited driving is also know as an “Italian tune-up�. In most cars this can be very beneficial. If you car experiences mostly in town stop and go traffic you also may want to use something like Lubro Moly’s Ventil Sauber (valve cleaner) and Jectron (injectors and fuel system cleaner) during the “spirited� driving to help clean up carbon and other deposits. If twisty and spirited driving are not your thing, then go for a good highway cruise with the engine running at 4500-5000 rpm. You will get poor gas mileage under this circumstances. You can also achieve the beneficial result from an automatic by locking out the overdrive or setting the car to something like D4. Manuals just don’t shift into 5th or 6th (what ever your top gear is).



Many times vehicles are driven such short distances that they don’t have sufficient time to really get all the fluids and parts to normal operating temperatures. When vehicles are used in this manner a lot carbon and other deposit can build up on some of the internals and slowly decrease performance and even effect emissions.



I have to go on a rant… as was mentioned the temperature gauges (water) on most cars are horrible indicators what temperature you car is operating at. First as was said water heats up faster than oil. Second the gauges are very inaccurate. In most cars you can sit in a traffic jam for 45 minutes in the summer and your gauge will never move from the center of normal. These gauges are engineered so that as long as the temperature is within a preset specification the gauge will read normal. In reality the temperature is varying consently with the driving conditions and the operation of the car. For example as the car sits with no air moving through the radiator the temperature will start to rise and at some temperature point a fan will be triggered to move air through the radiator to and cool things off. However during these operations the temperature gauge will not budge. My wife’s 328i is this way. Once the gauge gets in the middle it does not move. However, it is interesting to drive a car like the water cooled Porsche Boxster or Carrera because the temperature gauge for the water do not have the “numbnessâ€� of many cars. As you sit in traffic you can see the gauge raise, start moving again and the gauge will start to drop, the same can be observed when a cooling fan kicks on. The same is true for the oil temp gauges on the air/oil cooled Porsches. I don’t know why most manufacturers design their gauges with the built in numbness, is it because they think the general public will panic if they see their temperature gauges moving?



Back to the topic at hand, running your engine to redline will not damage it (that’s what limiters are for right :) ) and on some cars can be very beneficial. Honda’s Vtec engines are good example of an engine that should be run with high revs. These engines were designed to be driven at higher revs as that is where the power is, however, it seems that most people don’t like to drive them this way.
 
not only that, but they heat up(the oil does) faster than say a big v8 does, so about 10 minutes of normal driving, and your ready to open it up. Btw, hondas love revs, preferably in the 5 or 6 range. Although, i raced another civic today, same model, 1999 i think, and the only thing he did to get passed me was downshifted to second at 40 mph, which i just stopped and didn't even bother finishing it bc he had to sacfrice wear on his tranny just to pass me.
 
Wow, I'm impressed with the knowledge!



Geekysteve is right about the downshifting. It is a known fact especially in high performance cars that it's the downshift that usually causes engine failure. I don't have the experience that he does but I've read this time and time again.



To take a quote from bet993 "I don’t know why most manufacturers design their gauges with the built in numbness, is it because they think the general public will panic if they see their temperature gauges moving?".......YES!



I see this time and time again on the Mercedes Forum. The older Mercedes up until 1996 (I believe) displayed current temperatures of the coolant similar to the Porsche. There are tons of posts with people concerned that their gauge reached 100C even though the fans aren't designed to come on until 105C. I have to assume they stopped making them this way because so many people complained about it the car not running right.:nixweiss
 
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